The invention relates generally to lightning detection systems and, more particularly, to lightning detection systems for wind turbines.
Lightning is a random phenomenon in nature. Lightning parameters vary depending on geographical conditions and nature of lightning in terms of their intensity and impact on an object. Different lightning detecting techniques exist depending on the application. Wind turbines, in particular, are generally subjected to a high risk of lightning strikes as they are preferentially placed at high and windy locations in order to achieve high productivity.
In general, there are two commonly used lightning detection systems available commercially with wind turbines. One of the detection systems is based on the principle of magnetization. The detection system includes magnetic cards positioned in various parts of a wind turbine blade to detect lightning current passing through. After a lightning impact, the magnetic cards are read out manually by a card reader unit to measure a peak value of current. However, the system is unable to detect the number of lightning sequences striking a wind turbine between periods of two magnetic card readings.
Another detection system includes small antennas fixed on a body of a wind turbine tower in a wind turbine application. The antennas are used to detect lightning current and field that pass the wind turbine tower. Signals from the antennas are transformed from an electrical signal to an optical signal via an optical fiber to a control box. Output of the control box indicates a lightning impact. However, in most cases, the system has to be reset by an acknowledgement signal and an affected blade cannot be identified automatically.
The aforementioned lightning detection systems register only appearance of lightning events without registration of lightning event parameters or localization of impact. Therefore, a need exists for an improved lightning detection system that may address one or more of the problems set forth above.